1. Technical Field
The present disclosure relates to phase locked loops, and, more particularly, to a digital phase detector and a digital phase locked loop including the same.
2. Discussion of the Related Art
Generally, a phase locked loop is used to output a signal having a locked phase. A conventional phase locked loop is implemented by analog circuits that include a phase frequency detector, a charge pump, a loop filter, a voltage controlled oscillator, and a divider. However, the conventional analog phase locked loop may provide low accuracy and have high sensitivity to external noises.
To avoid these analog circuit issues, a digital phase locked loop has been implemented by digital circuits. Usually, in the digital phase locked loop, a digital frequency detector corresponding to the phase frequency detector of the analog phase locked loop is used. However, when a large size digital frequency detector is implemented it consumes high power, and the resultant digital phased locked loop can, in turn, become large in size and consume high power.